Many types of bruiseable fruits and vegetables are inspected, sorted and packed at processing plants for market. Such fruits and vegetables include apples, oranges, avocados, pears, onions, and the like. Such fruit and vegetable articles are typically sorted into groups of articles having common characteristics such as shape, weight and color. The weight, shape and color are properties which may be determined by a sorting apparatus that receives bulk quantities of articles, determines the properties of each article in sequence, and sorts each article into an appropriate groups based on its determined properties. Often such sorted articles are sold in bags with a pre-printed weight. For example, apples may be weighed on a scale in the sorting apparatus and then sorted into groups based on the determined weight, so that apples having a weight in a particular range are grouped together. The apples are then placed in a bag which contains apples having substantially uniform size and weight. Also, such articles may be sorted into groups depending on the optical or color characteristics of the surface of the articles. Optical devices such as a camera scan the article and the image is processed to determine the optical characteristics of the article, including size and color. For example, red delicious apples may be sorted based on the percentage light red, red, and dark red surface color; apples having common color characteristics may then be grouped together.
Such sorting by determined properties of an article has a number of benefits. Articles that have more valuable characteristics may be sold for a higher price. Consumers benefit by obtaining articles that are uniform in size, weight and appearance. For example, each apple in a bag has substantially similar characteristics, and one of the apples will be substantially the same as the next. As a result, the consumer gains additional confidence in the quality of the articles. Articles exhibiting less valuable characteristics, such as non-uniform size or bruises, may be selected by other value-added processing. For example, apples with non-uniform coloration may be sorted out for cooking into applesauce for canning or mashing to extract the juice for bottling.
Apparatus for sorting such fruit or vegetable articles have been described before. Such apparatus typically has a continuous conveyor carrying a plurality of cups adapted to hold the type of article being sorted. For example, cucumbers preferably have a longer cup than apples which preferably are held in square or rectangular cups. The shape and size of the cups vary depending on the type of article to be sorted and the manufacturer of the sorting apparatus. Each cup receives an single article of fruit or vegetable in a loading zone from a bulk supply of articles. The cups then pass in sequence through a property-determining zone to determine the characteristic or property for which the articles are to be sorted. For example, the articles are weighed on a scale in a weighing zone to determine the weight of the article in each cup. The cups then pass in sequence through a discharge zone where each article is selectively discharged at an appropriate discharge station to group together those articles having similar characteristics.
U.S. Pat. No. 4,254,877 issued to Rose describes a weight sizing apparatus having a plurality of discharge stations. An article discharges at a selected station onto a take-away conveyor which carries the article with others having a weight in the selected range for packing. To reach the take-away conveyor, the article first drops from a carrying cup onto a deflection ramp having a soft surface to cushion the fall of the article. The ramp then directs the article to the take-away conveyor for grouping with other articles. This sorting apparatus however has a disadvantage of subjecting the article to a free-fall drop, which may unnecessarily risk bruising or otherwise damaging the article.
U.S. Pat. No. 4,262,807 to Leverett describes an article carrying cup having lost motion in the vertical direction, thereby permitting the cup to be weighed independently of a conveyor to which the cup is attached. Each cup connects to a conveyor chain by a tow bar and a plurality of ribs extend downwardly from the lower portion of the cup to support the cup on a scale in a weighing zone. The cup moves vertically in a slat at the forward end so that the cup is held independently of the conveyor by the ribs on the scale.
Sorting may be accomplished by properties other than weight. U.S. Pat. No. 3,575,292 issued to Roda describes an apparatus that grades articles by size. The apparatus includes a parallel endless link chain carrying a plurality of spaced apart pairs of parallel rollers. An article is carried on a pair of adjacent rollers for sorting by size. The articles are carried in sequence under a series of grading slats that pivotally mount over the path of the chain. The vertical gap between the rollers on the chain and the slats is adjustable, and the gap sequentially narrows along the line of slats in the direction of travel of the chain. As the chain moves, a rim on each roller contacts a track in which the chain travels, causing the rollers to rotate and thereby cause the article to rotate. If the top of the article does not come into contact with a slat, the article rolls idle but remains on the rollers. The article continues to roll idle until the article is engaged by one of the slats. The article thus engaged then tends to roll in a reverse direction. This is caused by the frictional contact of the article with the slat and the movement of the chain. The chain continues to move, and the rotating rollers cooperate with the slat to cause the article to roll rearwardly from the rollers into a space between adjacent pairs of rollers. The article then falls onto a chute where it is gathered with other articles of a similar size.
U.S. Pat. No. 4,586,613 issued to Horii describes an apparatus for sorting articles carried separately on trays. The apparatus includes a variety of property-determining devices, including a scale and optical scanners for determining weight, size, color, and defects in the article. However, this apparatus has deficiencies in that the fruit or vegetable is placed in a predetermined position which is not changed until the article is discharged. Accordingly, bruises or color differences may be hidden from detection by the optical scanners.
Accordingly, there remains a need in the art for an article-holding cup that rotates the article held thereon for exposing the surface of the article to optical scanners in a sorting apparatus that determines the weight and the optical characteristics of the article during a single pass through a property-determining zone so that articles with like properties may be selectively grouped in a discharge zone.